Do-Sung Kim

P‐7: The Horizontal Electrodes Structure for High Aperture Ratio IPS Mode (H‐IPS mode)

We designed a new pixel layout to improve the aperture ratio of IPS mode TFT-LCD(H-IPS). This H-IPS pixel layout design has reduced the width of side common electrode used to minimize the cross talk and light leakage which is induced by interference between data bus line and side common electrode of conventional IPS mode. The side common electrodes of a pixel can be reduced by horizontal layout of interdigital electrode pattern where conventional IPS pixel designs have vertical layout of interdigital electrodes. We realized 15 inch XGA TFT LCD of H-IPS structure which has aperture ratio as much as 1.2 times of corresponding conventional IPS pixel design.

P‐23: Design Parameters for Using Charging Technique for TFT‐LCDs

In case of charging a large capacitor in a short time, We use a well-known pre charging technique(1), which is a method of charging a pixel two times at an interval of one gate pulse width. But there is a side effect of a pattern looking like out of focus. This phenomenon is caused directly by a different quantity of charging being introduced into two pixels which are two pixels apart vertically with each other. To remove this side efeect, we optimize the charging design parameter; Cst+Clc, Ion condition from TFT device. with the pre charging technique, A 120Hz 32″ WXGA TFT-LCD which has three times of Cst + Clc as compared to conventional IPS structure has been developed.

P-13: New Design of Advanced H-IPS(AH-IPS) Panel for High Aperture Ratio

We designed the new pixel layout of the AH-IPS, which has similar aperture ratio to the IPS with organic insulator. To improve the aperture ratio without organic insulator, we positioned the pixel electrode over the preceding gate on the base of the H-IPS structure and minimized the width of pixel and common electrodes. Additionally, we used a TCO (Transparent Conducting Oxide) as the common electrode. This AH-IPS can provide high aperture ratio and flexible design.

P-14: An Efficient Way to Drive H-IPS Mode using 2*2 Inversion Method

In case of applying 2×2 inversion driving method for H-IPS mode LCM, We can easily perceive the vertical line pattern phenomenon looking like a furrow. This phenomenon is caused directly by symmetrical coupling interference between both data bus lines of one pixel and pixel electrode and indirectly by three or four times of capacitance between data bus line and pixel electrode as compared to conventional IPS structure. To remove this phenomenon, we designed a optimum pixel layout to remove the vertical line pattern phenomenon. This H-IPS pixel layout design concept is having a asymmetry coupling interference between both data bus lines of one pixel and pixel electrode. With the optimum pixel layout, the vertical line pattern phenomenon which was happened in 20.1 inch 2×2 inversion driving UXGA TFT LCD of H-IPS structure was removed.